European Published Patent Application No. 1 449 720 describes a seat part situated next to the vehicle seat, which is capable of being folded into the storage space, and a seat back associated with the seat part but separate from it, which is capable of being folded away laterally.
U.S. Pat. No. 808,679 describes a folding vehicle seat capable of being folded up, which in the folded state may be slid from the side under an adjacent seat.
German Published Patent Application No. 689 03 290 describes a back seat for a motor vehicle capable of being folded over, which has a seat surface and two seat backs situated side by side, which are each equipped with device(s) for locking in the raised application position, both seat backs being supported by a common horizontal shaft, the latter being able to be swiveled about an axis between a raised application position of the seat bench and a folded-down position of the two seat backs and one of the seat backs being mounted on it in a swiveling manner.
German Published Patent Application No. 10 2004 011 137 describes a motor vehicle back seat system having at least one first seat component swiveling about an axis, which is lockable at least indirectly with the vehicle structure, and a swiveling second seat component situated offset in the axial direction of the axis, which is lockable with the first seat component, at least one double fitting being provided for swiveling and locking the first seat component and the second seat component.